An arm rest of this type should be able to support a load of about 80 daN. It is, however, desirable to provide a margin for safety and to provide the arm rest with an overload protector that responds at about 30 daN, that thus for example uncouples a toothed latching structure so that when this load limit is exceeded the arm-rest body can drop down to an abutment on the motor-vehicle body. Such an overload protector is known in general and is described in detail in above-cited German 295 12 686.
The overload protector according to German 295 12 686 has however the disadvantage that its parts are separated by quite some distance from the arm-rest support body and thus take up a considerable amount of space.
The arm rest according to EP 1,164,051 has primary and secondary parts with surfaces centered on a common axis (center axis), confronting each other, and formed like a jaw clutch with face teeth, the primary part mounted on the arm-rest body being pivotal and also axially movable. The latch teeth of EP 1,164,151 having blocking and sliding flanks like Hirth teeth or a jaw clutch make it possible with fairly small primary and secondary parts to withstand substantial angular load moments. In addition this known arm rest makes it possible for a control device to determine at what angular positions the primary and secondary parts mesh so that downward pivoting of the arm-rest body is blocked in the selected positions.
In EP 1,165,051 a compression spring coaxial with the secondary part and primary part presses the primary part fixed on the arm-rest body axially against the secondary part. The axial shiftability of the primary part is limited by a plate-shaped abutment fixed on the common central axle.
In order to prevent damage to such an arm rest according to EP 1,165,051 it is even preferable to set up the arm rest with an overload protector that responds at about 30 daN, that for example decouples the toothed latching structure so that when the load limit is exceeded the arm-rest body can be deflected downward to a position determined by a vehicle-body abutment. Such an overload protector is generally described for example in German 295 12 686.